Are You A Gardener? Prepare To Adjust Your Planting Season

This is the time of the year when backyard gardeners start seedlings or scan seed catalogs as they eagerly plan for spring. I’m actually writing this with potting soil under my fingernails from prepping a tray of buttercrunch lettuce and two new tomato varietals. But before you make those final decisions about what you put in the ground, you might want to check the latest USDA Plant Hardiness Zone Map, because most people will find that they’ve moved by at least one half-zone, and some have moved even more. 

If your gardening experience extends beyond occasionally grabbing a pack of marigold seeds at the hardware store or murdering a tomato on the balcony, odds are you already know this. The 2023 revised map came out two months ago and the shocking difference between that map and the previous version has been a big subject of discussion in gardening circles.

The maps are made by examining the average annual low temperatures in an area over a decade. Each half-zone change represents a 5-degree (Fahrenheit) shift, so most of the time the changes between one generation of the map and the next are small. That’s not true this year. Some locations have advanced by a full 10-degree zone and changes are almost universal.

This does not mean it suddenly got warmer where you live and you can expect 2024 to be that much warmer than years past. It means that climate change has already made it warmer and the USDA is just catching up. 

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